WASHINGTON, Sept 4: A key committee of the US Senate authorised President Barack Obama on Wednesday to use limited force against Syria, after adopting amendments that also called for changing “the military equation on the battlefield” in favour of the Syrian opposition.

The resolution would limit the expected military action to 60 or 90 days, narrow the conflict to Syria’s borders and prohibit US troops on Syrian soil.

The Senate Foreign Relations Committee also approved two amendments by a senior Republican Senator, John McCain, which called for improving military capabilities of the Syrian opposition.

The amendments, however, also made it clear that the end goal should be “a negotiated settlement that ends the conflict and leads to a democratic government in Syria”.

The 10 to seven votes, with one abstention, showed that some lawmakers were still hesitant to lead America to yet another war so soon after Iraq and Afghanistan.

The administration may find it even more difficult to persuade the House of Representatives to support its motion as it is dominated by the Republicans. However, traditionally the Republicans have been more eager than Democrats in endorsing US war efforts.

The authorisation must be approved by the full Senate and the House before taking effect.

Earlier, US Secretary of State John Kerry told a House committee that Arab countries had offered to reimburse the expenses of unseating President Bashar al-Assad if the United States took the lead militarily.

“With respect to Arab countries offering to bear costs…, the answer is profoundly yes,” Mr Kerry said. “They have. That offer is on the table.”

When a Republican lawmaker, Ileana Ros-Lehtinen, asked how much those countries would contribute, Mr Kerry said they had offered to pay for all of a full invasion.

“In fact, some of them have said that if the United States is prepared to go do the whole thing the way we’ve done it previously in other places, they’ll carry that cost,” Mr Kerry said.

“That’s how dedicated they are at this. That’s not in the cards, and nobody’s talking about it, but they’re talking in serious ways about getting this done.”

Later in the afternoon, the Foreign Relations Committee met again to vote on various amendments to President Obama’s proposal.

On Tuesday night, key Democrat and Republican members of the committee agreed on details of the plan, authorising President Obama to order limited strikes against Syrian military targets for 60 days. He could extend the window by another 30 days under certain conditions.

The resolution does not authorise the use of ground troops and insists on focusing the strikes at deterring and preventing Syria from carrying out future chemical weapons attacks. The measure also binds Mr Obama to present a strategy for bringing a political resolution to the Syrian crisis.

Republican Senator Rand Paul voted no, and unsuccessfully sought an amendment that would reaffirm Congress’s pre-eminent role in declaring war, as reflected in the 1973 War Powers Act. The committee left the constitutional issue unresolved by a 14-5 vote. Mr Paul is a staunch opponent of an attack on Syria.

The committee also rejected an amendment by Senator Tom Udall, a Democrat, that would have prohibited air and naval forces from being put into Syrian waters or airspace.